Aims: This study evaluated the effects on glycemic control of the addition of 2.5 mg glipizide GITS to metformin in patients with mild-to-moderate, but suboptimally controlled type 2 diabetes.
Methods: In this multicenter, double-blind, placebo-controlled study, 122 patients with type 2 diabetes inadequately controlled (A1c 7-8.5%) on metformin (> or =1000 mg/day for > or =3 months) were randomized to 16 weeks treatment with 2.5 mg/day glipizide GITS (n=61) or placebo (n=61), in addition to their current metformin dose. The primary efficacy variable was the change in A1c from baseline to endpoint. Changes in fasting plasma glucose (FPG), insulin concentrations, lipid profile and safety variables were also measured.
Results: The addition of glipizide GITS to metformin gave significantly greater improvements in mean A1c and FPG from baseline to endpoint than placebo addition (p<0.0002). Significantly more patients in the glipizide GITS group than in the placebo group achieved the target A1c level of A1c<7.0% (p<0.0001) and an A1c<6.5% (p<0.0033). Fasting insulin concentrations were similar in both groups and unchanged by treatment. Addition of glipizide GITS to metformin did not produce any significant or clinically relevant weight gain or changes in BMI. Both treatment regimens were well tolerated.
Conclusions: This study showed that the addition of 2.5 mg glipizide GITS to metformin significantly improved glucose control in patients with type 2 diabetes inadequately controlled by metformin monotherapy.